Given these are online cloud saved game files does the memory size really matter? I've used a 430 x 320 x 256 colour PNG which rocks up at about 31k extra. I guess if you're going for minimal through and through with your game that's fair enough. You could try less colour range which will help bring down the size further. 2 colour or 4 colour (like a BBC Micro) or 8 colour (Spectrum et al). Reducing the overall resolution size could help too, so it might just be Half the screen rather than the whole screen area and that will bring it down even further.
As for the visual quality, I did try it without the scanlines, but preferred the scanlines in the end. It looks retro and sometimes hides the scaling artifacts.
Viewing post in Title screen graphics
When compiled, all resources, including game data, game engine, fonts and graphics, are save in an HTML file. This needs to be downloaded to play. Obviously, the smaller the file, the quicker the download. I'm testing and fine tuning now. I might revisit the graphics later, but I do like my title screen, as it reflects the story and "flavour" of the game very well.
That's fair comment. Given the size of these games I doubt we're looking at huge Gigabytes of file here though (are we?). I wouldn't worry about it too much. Unless you've just created a monster of an adventure, in which case that sounds very interesting. ;-) For instance my adventure which is almost done weights in at a merge 1.78mb (its got a fair number of locations, masses of scenery objects and items and text and a new font and loading screen), which would take all of 5 seconds to download if that. ;-)
edit: Having said that I realise people have differing download rates, I have a whopping 196 mb/s download, while others have just 2 mb/s but even then this should take only seconds to download.
Even though adventuron is technically 1.5mb, Html in modern browsers is now served gzipped, which means the engine compressed is about 370k. In addition, return visits are cached so no download, and JavaScript is only compiled the first visit them the compiled version is reloaded from the cache too. Should be quick even on slow mobile connections.
The editor gets slower with more assets, but you really need a lot to make it properly slow these days ( I sped it up by a factor of 20x recently). I can optimize it a lot more, but like I said in the jam notes, I'm aiming not to add a lot of features at this point in time. You really don't need a lot of assets in a text only jam.